摘要:
为研究预应力全长注浆锚索在围岩加固方面相对于端锚锚索的优势，基于中性点理论，分析锚索轴力、剪应力分布特征；建立全长注浆预应力锚索力学模型，推导巷道围岩任一点在弹性、弹塑性及塑性状态下表面位移解析解；研究预应力全长注浆锚索对围岩径向及切向变形的控制作用；以晋城煤业集团有限公司某矿33042巷9号联络巷为工程背景，分析未受采动影响及采动影响下常规锚索及预应力全长注浆锚索支护效果。研究结果表明：靠近巷道表面围岩，围岩变形大于锚索，锚固体表面剪应力指向巷道自由面，在围岩深部，围岩变形小于锚索，锚固体剪应力指向围岩深处，两侧剪应力相反，锚固体轴向拉力沿锚索长度方向呈曲线变化，且在中性点处最大；在未受采动影响下，普通锚索与预应力全长注浆锚索支护巷道变形趋势相同，巷道开挖初期变形剧烈，之后趋于平缓，锚索受力均匀、工作状态平稳，预应力全长注浆锚索相比端锚锚索能够减少顶底板移近量50%；采动影响期间，预应力全长注浆锚索支护下，顶底板移近量和两帮移近量分别比端锚锚索减少21.1%和22.1%，锚索受力普遍增加，且变动不大，未出现锚索破断现象；预应力全长注浆锚索相较于端锚在围岩径向及切向变形控制方面具有明显优势且能够很好地解决复合顶板巷道受剪切作用导致锚索破断的问题。
Abstract:
In order to study the advantages of prestressed full-length grouting anchor cable compared with end anchor cable in surrounding rock reinforcement, the distribution characteristics of axial force and shear stress of anchor cable were analyzed based on the neutral point theory;the mechanical model of the full-length grouting prestressed anchor cable was established to deduce the analytical solution of the surface displacement of any point of the surrounding rock of the roadway under elastic, elasto-plastic and plastic states;the control effect of prestressed full-length grouting anchor cable on the radial and tangential deformation of surrounding rock was studied. Taking 9# connecting lane of No.33042 lane in a coal mine of Jinmei Group as the engineering background, the support effect of conventional anchor cable and prestressed full-length grouting anchor cable without and under the influence of mining was analyzed. The research results show that the deformation of surrounding rock near the roadway surface is greater than that of anchor cable, and the shear stress on the surface of the anchor body points to the roadway free surface. In the deep part of surrounding rock, the deformation of surrounding rock is less than that of anchor cable, and the shear stress of anchor solid points to the deep part of surrounding rock, and the shear stress of both sides is opposite. Axial tension of anchor solid shows curve distribution, and it is the largest at the neutral point;under the influence of mining, the deformation trend of ordinary anchor cable and prestressed full-length grouting anchor cable support roadway is the same. The deformation of the roadway is severe at the beginning of excavation, and then tends to be gentle. The stress full-length grouting anchor cable can reduce the approaching amount of the roof and floor by 50%;during the mining impact period, under the support of the pre-stressed full-length grouting anchor cable, the approaching amount of the roof and bottom plate and the two sides are reduced by 21.1% and 22.1% respectively, the stress of anchor cable is generally increased, and the change is small, and there is no anchor cable breaking phenomenon;compared with the end anchor, the prestressed full-length grouting anchor cable has obvious advantages in the control of the radial and tangential deformation of surrounding rock, and it can solve the problem of anchor cable breaking caused by the shear action of composite roof roadway.
百度学术
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